Polysiloxanes, especially polydimethylsiloxanes have long been used in applications where lubricity, hydrophobicity, low free-surface energy, low temperature flexibility, and biocompatibility and/or oxygen permeability are of great concern. In addition to the specific synthetic techniques for making silicone rubber, most of the general techniques of polymerization have also been used to make silicon containing polymers and especially block copolymers with a desirable combination of properties. These techniques include free radical polymerization of methacrylate functional polydimethylsiloxanes and, more commonly, synthesis of step-growth polymers, such as polyesters, polyurethanes and polyamides. Useful polysiloxane intermediates for this purpose are polydimethylsiloxanes of either linear or branched structure which contain one or more reactive groups.
Free radical and radiation curable silicone polymers as well as modified silicone polymers are well known in the art. U.S. Pat. No. 4,477,548 teaches curable coating compositions comprised of siloxy-containing acrylated urethanes or siloxy-containing polycarbinol and an acrylated urethane with multifunctional acrylates. Radiation curable coating compositions from acrylated urethane silicones, formed from the reaction of a silicone carbinol, a polyisocyanate, and a hydroxy-functional acrylate are taught in U.S. Pat. No. 4,369,300.
Photocurable silicone compositions derived from reaction of amino-containing silicone compounds with glycidyl acrylate functional materials are described in U.S. Pat. No. 4,293,397, and U.S. Pat. No. 4,603,086 discloses photocurable silicone compositions derived from reaction of amino-containing silicone compounds with acrylates. U.S. Pat. No. 4,563,539 discloses acrylofunctional silicones from the product of reacting aminoalkylsilicones with isocyanatoacrylates. U.S. Pat. No. 4,605,712 relates to polysiloxanes containing at least one vinyl group connected to polysiloxane segments through intervening alkylene-urea or -urethane linkages.
Polysiloxane-containing polymers derived from azlactones are disclosed in U.S. Pat. Nos. 4,485,236, 4,619,867, 4,699,843, 4,777,217, and 4,852,969. Hydrosilation or hydrosilation reaction products are not suggested or taught in these references.